Join Date: Jun 2009
Location: Southeastern Pennsylvania
So my 66 coupe is at the body shop now getting some rust repair done. I appear to have a very small leak in the cowl vents, nothing crazy but some water is getting through. I can’t really afford to pull the whole cowl apart and replace the panels. But the car will be parked outside and driven regularly, even in the occasional California rain, so I need to do something.
You're fixing the wrong thing. The leaky cowl is what ruined the floors.
I don’t love the look of the plastic covers, so I am thinking about just welding the vents closed and smoothing the cowl to keep water out.
You're not supposed to drive the car with the cowl cap installed.
Obviously there could be a little water intrusion through the wiper arm holes, but I figure that would be minimal. I plan to use an aftermarket AC system that uses recirculating air, so I don’t see why I would need the vents...
A recirculating system does a very poor job of defogging the windshield, for one thing.
Thoughts? Any reasons I shouldn’t do this? Would love to hear any ideas/opinions, especially from anyone that has done this.
Having the top of the cowl properly welded shut, filled, smoothed, and painted would cost roughly the same as having it fixed.
A better choice would be to examine the problem. Is it a few pinholes or is the whole bottom rotted out?
If the latter, you have no choice but to fix it. The cowl is a structural part, joining the left and right side of the body together.
If the former, is it the bottom of the cowl, or the standpipes? For many years, the standard repair for that was plastic inserts, sealed in place. In my Dad's 68, it was just a few pinholes in those. I jacked up the right side of the car, plugged the drain, and filled the left side of the cowl with liquid undercoating, drained it, and repeated with the other side. It never leaked again.
Amateur restorer. Well, sometimes I have been paid for it. But not right now.